From 241c3a1d8001fc5a30e2af4b4636b48e6f99690a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jos=C3=A9=20Fonseca?= Date: Mon, 31 Aug 2009 10:22:36 +0100 Subject: [PATCH] llvmpipe: Fallback to element-wise comparisons when no comparison intrinsic is available. Although selection of vector elements is valid LLVM IR, no machine target supports it yet. This is a last-resort option, but it allows llvmpipe to be used on any target supported by LLVM without modifications. Obviously better performance is attainable by emitting SIMD intrinsics where otherwise LLVM doesn't. --- src/gallium/drivers/llvmpipe/lp_bld_logic.c | 47 ++++++++++++++++++++- 1 file changed, 45 insertions(+), 2 deletions(-) diff --git a/src/gallium/drivers/llvmpipe/lp_bld_logic.c b/src/gallium/drivers/llvmpipe/lp_bld_logic.c index d6dfd853422..8631efd6c3e 100644 --- a/src/gallium/drivers/llvmpipe/lp_bld_logic.c +++ b/src/gallium/drivers/llvmpipe/lp_bld_logic.c @@ -51,6 +51,8 @@ lp_build_cmp(struct lp_build_context *bld, LLVMValueRef zeros = LLVMConstNull(int_vec_type); LLVMValueRef ones = LLVMConstAllOnes(int_vec_type); LLVMValueRef cond; + LLVMValueRef res; + unsigned i; if(func == PIPE_FUNC_NEVER) return zeros; @@ -67,7 +69,6 @@ lp_build_cmp(struct lp_build_context *bld, LLVMValueRef args[3]; unsigned cc; boolean swap; - LLVMValueRef res; swap = FALSE; switch(func) { @@ -218,7 +219,28 @@ lp_build_cmp(struct lp_build_context *bld, assert(0); return bld->undef; } + +#if 0 + /* XXX: Although valid IR, no LLVM target currently support this */ cond = LLVMBuildFCmp(bld->builder, op, a, b, ""); + res = LLVMBuildSelect(bld->builder, cond, ones, zeros, ""); +#else + debug_printf("%s: warning: using slow element-wise vector comparison\n", + __FUNCTION__); + res = LLVMGetUndef(int_vec_type); + for(i = 0; i < type.length; ++i) { + LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), i, 0); + cond = LLVMBuildFCmp(bld->builder, op, + LLVMBuildExtractElement(bld->builder, a, index, ""), + LLVMBuildExtractElement(bld->builder, b, index, ""), + ""); + cond = LLVMBuildSelect(bld->builder, cond, + LLVMConstExtractElement(ones, index), + LLVMConstExtractElement(zeros, index), + ""); + res = LLVMBuildInsertElement(bld->builder, res, cond, index, ""); + } +#endif } else { LLVMIntPredicate op; @@ -245,10 +267,31 @@ lp_build_cmp(struct lp_build_context *bld, assert(0); return bld->undef; } + +#if 0 + /* XXX: Although valid IR, no LLVM target currently support this */ cond = LLVMBuildICmp(bld->builder, op, a, b, ""); + res = LLVMBuildSelect(bld->builder, cond, ones, zeros, ""); +#else + debug_printf("%s: warning: using slow element-wise vector comparison\n", + __FUNCTION__); + res = LLVMGetUndef(int_vec_type); + for(i = 0; i < type.length; ++i) { + LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), i, 0); + cond = LLVMBuildICmp(bld->builder, op, + LLVMBuildExtractElement(bld->builder, a, index, ""), + LLVMBuildExtractElement(bld->builder, b, index, ""), + ""); + cond = LLVMBuildSelect(bld->builder, cond, + LLVMConstExtractElement(ones, index), + LLVMConstExtractElement(zeros, index), + ""); + res = LLVMBuildInsertElement(bld->builder, res, cond, index, ""); + } +#endif } - return LLVMBuildSelect(bld->builder, cond, ones, zeros, ""); + return res; }